Furnace fire-grate.



Patented July 20, 1915.

3 SHEETS-SHEET I.

Q l \s 5.: Q

I m ll 0 0 J. CAREW.

FURNACE FIRE GRATE.

APPLICATION FILED JUNE 12, 1913.

J. CAREW.

FURNACE FIRE GRATE.

APPLICATION FILED JUNE 12, 1913.

Patented July 20, 1915.

3 SHEETS-SHEET 2.

FIG. 2.

VII asses J. CAREW.'

FURNACE FIRE GRATE.

I APPLICATION HL'ED JUNE 12.1913. 20,

'3 SHEETS-SHEET 3.

c C K F I We [T 1116.5. J41 1 WWW JAMES CABEW, OF LIVERPOOL, ENGLAND.

FURNACE FIRE-GRAI'IE.

Specification of Letters Patent.

Patented July 20, 191 5.

IApplication filed June 12. 1913. Serial No. 772,306.

'To all whom it may concern Be it known that I, JAMES CAREW, subject of the King of Great Britain, residing in Liverpool, in the county of Lancaster, in the Kingdom of England, have invented certain new and useful Improvements in Furnace Fire-Grates, of which the following is a specification.

The present invention relates to that kind of furnace wherein the main fire grate is composed of fire bars having air conduits passing longitudinally through them, and wherein at the back of the main grate there is a separate or auxiliary grate of removable sloping fire bars also having longitudinal air conduits corresponding to and forming continuations of those in the firebars of the main grate. In this'kind of furnace, each sloping hollow bar has hitherto been hooked at top on a back bearer, while its lower end was socketed on to a spigot on the corresponding hollow main bar, so that they were practically in a single length jointed together; in fact the heat of the furnace practically welded the sloping bars to the main bars. Now according to the present invention, the

jointing together of the hollow upwardly sloping bars, and the hollow main bars, is dispensed with, and my improvement is characterized in that the lower ends of the hollow sloping bars and the adjacent ends of the hollow main bars are independently interlocked in position by a bearer, but without obstructing the passageway through the bars, so that when any particular bar is burnt or worn, it can be removed and replaced without removing any of the other bars.

In the accompanying drawings, Figure 1 is a sectional side elevation illustrating the disposition of my invention in the furnace flue of a boiler; Fig. 2, a view looking at the front of the bridge with some of the bars removed; and Fig. 3 a plan view; Fig. l is a vertical sectional view partly broken away, showing a slight modification of the interlocking connection; and Fig. 5 is a horizontal sectional plan view of the form of device shown in Fig. 4, with part of the bridge wall bars removed.

In these figures, A are the main firebars resting on the front end of the usual deadplate 13, and at the rear end on the rest C;

D are the upwardly sloping bars resting or hooked at top on the back bearer E, their lower ends resting on the rest C. This back bearer E consists of a chair plate, being formed of an upstanding part E, the forward projecting flange of which forms the rest C. In Figs, 1, 2 and 3, this rest has cast on 1t a vertical web with lateral flanges or beads G H at the top. The rear endso-f the main bars A are so shaped as'to fit against the web between the rest C and the flange G.

C, and has a flange G at the forward side.

, In Figs. 4 and 5, the rest C carries a vertical web whose base flange F has spaced ribs F, 'so as to leave an air space N, which forms an interstice, while at the top this vertical web has a flange G at the forward side. I The rear ends of the main fire bars A are so shaped as to fit against the web, between the rest C and the flange G, so as to interlock therewith. The lower ends of the sloping bars 1) have a cut away portion so that the forward part rests on the flange G, while the rearward part rests on the rest C in the space'between the base flange F and a stop bar I afiixed to the rest 0. Thus both.

sets of bars are interlocked with the rest C,

so that the rear, ends of the main bars A interlock with it the same as hereinbefore described, but the rear of the web has no flange H, but there is instead a stop bar I affixed to the rest C. The lower ends of the sloping bars D are so shaped as to rest on the flange G, andbetween the web and the stop bar I. There are air conduits J passing' through the bars, these conduits 'J comme'ncing atfthe underside of the main bar near the front end, and passing longitudinally through the bar tothe other end and through the upsloping bars, so that air frown below the firegrate can pass through the bars into the combustion chamber or'smoke box to assist in producing more complete combustion and keep the bars cool, and the air is heated in its passage thus supplying hotter air than can be obtained in the ordinary way. I am aware that the conduits through firebars have commenced at the front end and have opened endwise, and not at the under side. In this connection, my improvement consists in making the conduits so as to commence at the under side 1 near the front end. To keep the conduits J through the bars clear, steam can be blown through the bars by means of a jet S. Ports K are made in the web so as to connect the conduits J in one set of bars A with those in the other set D. The conduits J in the sloping bars D adjacent to the rest C are made tapering at L so as to receive the air current as it flows through the ports K. The tapering holes extend to the bottom of the bars D in such manner that the web and flange G lie substantially in the mouth of the tapering hole. The air current issuing through the ports K enters the conduits in the sloping bars, and is discharged at the top end of the sloping bars into the combustion chamher or smoke box. Thus the passage of air from the bars A to the bars I) is facilitated, and the bars locked to the rest C cannot get displaced, as when a pricker bar is used by the fireman, thus insuring that the conduits in the respective bars shall lie in line, and ash cannot penetrate between the adjacent ends of the bars. Besides the usual air spaces P between the bars, small vertical air channels Q are provided between the bars I) at the top and where they rest or hook in the back bearer E. Air entering the chamber R penetrates through these air channels Q and discharges itself at the top, the bars D fitting the back bearer loosely so as to allow air to pass, the object being to prevent clinker accumulating on the top of the sloping bars. In cases where the furnace tube T is corrugated, the bars at the side of the furnace are shaped at U to fit the corrugations.

It will be evident that by this invention, when all the bars are placed side by side in position, the whole by reason of the upstanding bars form a hollow fire bridge with interstices in front. Any individual bar or all the bars can very readily be removed by simply raising them off the back bearer E, or they can be easily replaced and the whole arrangement is of the simplest possible character.

I declare that what I claim is 1. In a firegrate, the combination of a rest (1 having afiixed to it a vertical web with lateral flange G, spaced ribs F and stop bar I, hollow main fire bars whose rear ends are so shaped as to come against the web between the rest and the flange G, hollow sloping fire bars at the back of the main bars whose lower ends are so shaped as to rest on the flange G and come against the web between it and the stop bar I, and ports in the web to connect the conduits in the main bars with those in the sloping bars.

2. In a firegrate, the combination of a rest C having aflixcd to it a vertical web with ports therein, main fire bars whose rear ends are so shaped as to interlock with said rest at one side, sloping fire bars whose lower ends are adapted to interlock with said rest at the other side, and longitudinal air passages through the fire bars coinciding with the ports in the web, those in the sloping bars being splayed or tapered at the lower end, so as to receive the air current issuing through the ports.

3. In a firegrate, the combination of a rest C having aflixed to it a vertical web with ports therein, main fire bars whose rear ends are so shaped as to interlock with the said rest at one side, sloping bars adapted to interlock with the said rest at the other side, longitudinal air passages through the bars coinciding with the ports in the web, the said air passages commencing at the under side of the main bars near the front end.

4. In a firegrate, the combination of a rest C having aflixed to it a vertical web with ports therein a back bearer, main fire bars whose rear ends are so shaped as to interlock with the said rest at one side, sloping bars hooked at top on to the back bearer and adapted to interlock with the said rest at their lower end, longitudinal air passages through the bars coinciding with the ports in the web, and air channels Q between the hollow sloping bars at the top end, where they hook on the top of the back bearer.

In witness whereof, I have hereunto signed my name this 4: day of June 1913, in the presence of two subscribing witnesses.

JAMES CAREW.

Witnesses:

G. C. DYMOND, R. W. W ILLIAMS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. 0. 

